The dynamics of oleic acid solubilization by aqueous sodium taurodeoxycholate, a model fatty acid digestion system, was studied at 37(DEGREES)C. Steady state stirred experiments provided evidence of enhanced solubilization rates under conditions similar to those present for the physiologic process of fat digestion. Enhanced rates were attributed to the formation of an oleic acid/aqueous surfactant liquid crystalline phase at the liquid/liquid two phase boundary. This interfacial phase was capable of being sheared and dissipated under flow conditions. Steady state solute fluxes under non-flow conditions were consistent with the diffusion of mixed aggregates or microemulsion droplets. An unsteady state quiescent experimental technique was employed to determine the correct interfacial boundary condition for the surfactant mediated solubilization of oleic acid. Results indicated the process to be surfactant diffusion controlled. The interfacial incorporation of solute into the micellar phase was deemed to be rapid. The effective diffusivity of oleic acid in aqueous surfactant solutions was found to be a strong function of the physical and chemical status of the acid as well as the type of surfactant employed as a solubilizer. All results are discussed in regards to the process of fat digestion in humans. The effects of solution pH, NaCl concentration and surfactant concentration are also presented.